微电子工艺17zhang课件

第17章离子注入1掺杂原因：本征硅导电能力很差。在硅中加入少量杂质，结构和电导率变化。2本章目标1. 解释掺杂在硅片制造过程中的目的和应用.2. 讨论杂质扩散的原理和过程.3. 对离子注入有整体的认识，包括优缺点.4. 讨论剂量和射程在离子注入中的重要性.5. 列举离子注入机的５个主要子系统.6. 解释离子注入中的退火效应和沟道效应.7. 描述离子注入的各种应用.

3具有掺杂区的CMOS结构n-channelTransistorp-channelTransistorLIoxidep–epitaxiallayerp+siliconsubstrateSTISTISTIn+p+p-welln-wellp+p–p+p–p+n+n–n+n–n+ABCEFDGHKLIJMNOn+nn++p+pp++Figure17.1

5CMOS制作中的一般掺杂工艺6离子注入在硅片流程中UsedwithpermissionfromLanceKinney,AMDImplantDiffusionTest/SortEtchPolishPhotoCompletedwaferUnpatternedwaferWaferstartThinFilmsWaferfabrication(front-end)Hardmask(oxideornitride)AnnealafterimplantPhotoresistmaskFigure17.2

717.2扩散1.扩散原理三步预扩散推进激活杂质移动固溶度横向扩散2.扩散工艺硅片清洗杂质源

9硅中的杂质扩散DisplacedsiliconatomininterstitialsiteSiSiSiSiSiSiSiSiSic)MechanicalinterstitialdisplacementSiSiSiSiSiSiSiSiSia)Siliconlatticestructureb)SubstitutionaldiffusionSiSiSiSiSiSiSiSiVacancyDopantd)InterstitialdiffusionSiSiSiSiSiSiSiSiSiDopantininterstitialsiteFigure17.4

10扩散原理

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扩散流方程1/17/2023扩散系数与温度有关D0：扩散率，E：扩散工艺激活能，k0：玻耳兹曼常数，T：绝对温度。3－613硅中的固溶度极限1100°CTable17.3

14扩散工艺扩散8个步骤:1. 进行质量测试以保证工具满足生产质量指标.2. 使用批控制系统，验证硅片特性.3. 下载包含所需工艺参数的工艺菜单.4. 开启扩散炉，包括温度分布.5. 清洗硅片并浸泡HF，去除自然氧化层.6. 预淀积：把硅片装入扩散炉，扩散杂质.7. 推进：升高炉温，推进并激活杂质，然后撤出硅片.8. 测量、评价、记录结深和电阻.

1517.3离子注入1.概况控制掺杂浓度（数量、深度）离子注入的优点离子注入的缺点2.离子注入参数剂量射程

17控制掺杂浓度、深度a) 低掺杂浓度(n–,p–)浅结(xj)MaskMaskSiliconsubstratexjLowenergyLowdoseFastscanspeedBeamscanDopantionsIonimplanterb) 高掺杂浓度(n+,p+)和深结(xj)BeamscanHighenergyHighdoseSlowscanspeedMaskMaskSiliconsubstratexjIonimplanterFigure17.5

18离子注入机示意图IonsourceAnalyzingmagnetAccelerationcolumnIonbeamPlasmaProcesschamberExtractionassemblyScanningdisk19离子注入的优点1. 精确控制掺杂浓度2. 很好的杂质均匀性3. 对杂质深度很好控制4. 产生单一离子束5. 低温工艺6. 注入的离子能穿过薄膜7. 无固溶度极限Table17.5

21缺点1.辐射损伤。高温退火修复。2.设备复杂（比扩散）注入剂量22射程能量电子阻止Se、核阻止Sn23杂质离子的射程和投影射程IncidentionbeamSiliconsubstrateStoppingpointforasingleionRpDRpdopantdistributionFigure17.7

25投影射程图ImplantationEnergy(keV)ProjectedRange,Rp(mm)101001,0000.010.11.0BPAsSbImplantingintoSiliconFigure17.8

RedrawnfromB.El-Kareh,FundamentalsofSemiconductorProcessingTechnologies,(Boston:Kluwer,1995),p.38826注入杂质能量损失SiSiSiSiSiSiSiSiSiSiSiSiSiSiSiSiSiSiSiSiSiSiSiSiX-raysElectroniccollisionAtomiccollisionDisplacedSiatomEnergeticdopantionSiliconcrystallatticeFigure17.9

2717.4离子注入机离子源引出电极（吸极）和离子分析器加速管扫描系统工艺室退火沟道效应颗粒

29离子源和吸极装配图UsedwithpermissionfromAppliedMaterialsTechnology,PrecisionImplanter9500

Figure17.11

ExtractionassemblySourcechamberTurbopumpIonsourceinsulatorBernasionsourceassemblyArcchamberExtractionelectrodeExtractionassemblyIonbeam30Bernas离子源装配图前板狭缝起弧室灯丝电子反射器气体入口5V电子反射器Anode+100V起弧室气化喷嘴电炉气体导入管DI冷却水入口掺杂剂气体入口UsedwithpermissionfromAppliedMaterialsTechnology,PrecisionImplanter9500Figure17.12

31离子源和吸极交互作用装配图UsedwithpermissionfromAppliedMaterialsTechnology,PrecisionImplanter9500

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----------NSNS120VArc吸出组件IonSource60kVExtraction2.5kVSuppressionSourcemagnetsupply5VFilamentToPA+IonbeamTerminalreference(PAvoltage)SuppressionelectrodeGroundedelectrodeArcchamberFigure17.13

32分析磁体石墨IonsourceAnalyzingmagnetIonbeamExtractionassemblyLighterionsHeavyionsNeutralsFigure17.14

339.2.1硅片制造厂的分区概述—离子注入34离子注入机分析磁体35加速管100MW100MW100MW100MW100MW0kV+100kV+80kV+20kV+40kV+60kV+100kVIonbeamIonbeamToprocesschamberElectrodeFromanalyzingmagnetFigure17.15

36剂量与能量图邻近吸收PresentapplicationsEvolvingapplicationsPolydopingSource/drainDamageengineeringBuriedlayersRetrogradewellsTriplewellsVtadjustChannelanddrainengineering0.1110100100010,0001017101110121013101410151016Energy(keV)Dose(atoms/cm2)UsedwithpermissionfromVarianSemiconductorEquipment37高能注入机的线性加速器SourceAtomicmassanalysismagnetLinearacceleratorFinalenergyanalysismagnetScandiskWaferFigure17.17

38空间电荷中和+++++++++++++++++++++++++Crosssectionofbeamwithspacechargeneutralization+++++++++++++++++++++++++Crosssectionofbeamblow-upDopantionSecondaryelectronFigure17.18

39中性束流陷阱SourceAnalyzingMagnetAcceleratorNeutralbeamtrapFocussinganodeY-axisdeflectionX-axisdeflectionNeutralbeampathWaferIonbeamGroundedcollectorplateUsedwithpermissionfromVarianSemiconductorEquipmentFigure17.19

40硅片的静电离子束扫描+IonbeamY-axisdeflectionX-axisdeflectionWaferTwistTiltHighfrequencyX-axisdeflectionLowfrequencyY-axisdeflectionFigure17.20

41注入阴影效应Resista)MechanicalscanningwithnotiltIonbeamb)ElectrostaticscanningwithnormaltiltResistIonbeamFigure17.21

42离子注入硅片的机械扫描OuterscanradiusInnerscanradiusImplantarea(calculated)SpillovercupRotationIonbeamUsedwithpermissionfromVarianSemiconductorEquipment,VIISion80IonImplanterFigure17.22

43控制硅片充电的电子喷淋AdaptedfromEatonNV10ionimplanter,circa1983++++++++++++++++++++++++++++++++++++++++++Ionbeam-BiasedapertureElectrongunSecondaryelectrontargetSecondaryelectrons+Ion-electronrecombinationWaferFigure17.23

44控制硅片充电的等离子体喷淋-BiasedapertureIonbeamNeutralizedatomsWaferscandirectionCurrent(dose)monitorPlasmaelectronfloodchamberArgongasinletElectronemissionChamberwall+++++++++++++++++++++++++SNSN++++++++ArArArFigure17.24

45离子注入机的终端台PhotographprovidedcourtesyofInternationalSEMATECHPhoto17.3

46注入工艺腔的硅片传送器UsedwithpermissionfromVarianSemiconductorEquipment,VIISion200IonImplanterVIISion终端台ProcessChamberTerminalSubsystemSourceSubsystem注入子系统Operatorinterface片架真空锁硅片传送器ScandiskVideomonitorWallFigure17.25

47法拉第杯电流测量RedraawnfromS.Ghandhi,VLSIFabricatonPrinciples:SiliconandGalliumArsenide,2ded.,(NewYork:Wiley,1994),p.417ScanningdiskwithwafersScanningdirectionFaradaycupSuppressorapertureCurrentintegratorSamplingslitindiskIonbeamFigure17.26

48硅单晶的退火RepairedSilatticestructureandactivateddopant-siliconbondsb)Silatticeafterannealinga)DamagedSilatticeduringimplantIonBeamFigure17.27

49退火1.不退火的害处：扩散或注入的杂质没有被激活，不能成为施主或受主。2.退火的好处：激活杂质，修复晶格缺陷。（注入造成的）原理：500°C修复晶格，950°C激活1.高温炉退火，800-1000度退火30分钟，导致杂质的再扩散。2.快速热处理RTA：1000°下短暂时间？瞬时增强扩散：严格控制50沿<110>轴的硅晶格视图UsedwithpermissionfromEdgardTorresDesignsFigure17.28

51离子入射角与沟道UsedwithpermissionfromEdgardTorresDesigns<111><100><110>Figure17.29

52来自颗粒沾污的注入损伤MaskMaskSiliconSubstrateBeamscanIonimplanterParticlecreatesavoidinimplantedareaFigure17.30

5317.5离子注入的发展趋势不同的离子注入工艺深埋层倒掺杂阱穿通阻挡层阈值电压调整轻掺杂漏极(LDD)源/漏注入多晶硅栅沟槽电容超浅结绝缘体上硅(SOI)

541深埋层Figure17.31

n-wellp-wellp-Epilayerp+Siliconsubstratep+Buriedlayer倒掺杂阱552倒掺杂阱RetrogradeWelln-wellp-wellp+Buriedlayerp+Siliconsubstraten-typedopantp-typedopantp++n++Figure17.32

563穿通阻挡层n-wellp-wellp+Buriedlayerp+Siliconsubstraten-typedopantp-typedopantp+p++n+n++Figure17.33

574.阈值电压调整n-wellp-wellp+Buriedlayerp+Siliconsubstraten-typedopantp-typedopantp+p++pn+n++nFigure17.34

585.LDD6.源漏注入++++++++----------++++++++++++++++----------------n-wellp-wellp+Buriedlayerp+Siliconsubstratep+S/Dimplantn+S/DimplantSpaceroxideDrainSourceDrainSourceb) p+andn+Source/drainimplants (performedin